1. Field of the Invention
The present invention is related to a spark plug, and more particularly, to a spark plug that is capable of removing the remaining electric charges thereof.
2. Description of Related Art
Conventionally, engines and ignition systems are used together to provide motive power for automobiles. An engine usually has several cylinders. Each of the cylinders has a cylinder head with a spark plug. Furthermore, an ignition system generally has a battery, an ignition switch, an ignition coil, a distributor and spark plug. When the ignition switch is turned on, the electric current first passes through the primary coil of the ignition coil. Then, the breaker point of the distributor is opened quickly to produce a high-voltage current via the electromagnetic effect and the high-voltage current is delivered to a high-voltage input end of the distributor via a secondary coil of the ignition coil. Finally, the distributor passes the high-voltage current to the spark plugs one by one via its high-voltage output ends to drive the spark plugs to produce sparks and thereby ignite the blended gas inside the cylinders to provide the power of the engine.
A conventional spark plug includes an insulating body, a center electrode and a conductive housing having a side electrode. The center electrode and side electrode of the spark plug are generally positioned inside a combustion chamber of a cylinder. When the ignition system passes the high-voltage current to the center electrode of the spark plug to produce a spark, some electric charges may remain in the side electrode of the conductive housing. It not only affects the usage of the spark plug and the efficiency of the engine but also possibly produces small sparks to cause unexpected damage.